Ejector



Oct. 21 1924.

K. BAUMANN EJEcToR Filed March 16, 1918 3 Sheets-Sheet. 1

Fig. 3.

- IN V EN TOR.

WEMMWW "ATTORNEY;

-K.BAUMANN EJECTOR 1 Filed March 16, 1918 3 Sheets-Sheet 2 v Fig-4' 5 INVENTOR.

Oct. 21 1924. 1,512,156

K. BAUMANN EJECTOR Filed March 16, 1918 3 SheetLs-Sheet. 5

Ill

I I a 'WITNESS I INVENTOR ATTGRNEY imparting to the entrained fluid an increased prior to entrainment in a spirally a device embodying my invention;

Patented Oct. 21, 1924.

UNITED STATES 1,512,156 PATENT OFFICE.

KARL BAUMANN, O'F URMS'ION, ENGLAND, ASSIGNCR TO WESTINGHOUSE ELECTRIC & MANUFACTURING (30., A CORPORATION OF PENNSYLVANIA.

Application filed March 16, 1918. Serial No. 222,824.

To all whom it may concern:

Be it known that I, KARL BAUMANN, a citizen of the Confederation of Switzerland, and a resident of Urmston, in the county of Lancaster, England, have made a new and useful Invention in Ejectors, of which the following is a specification.

My invention relates to ejectors and has particular reference to radial-flow ejectors in which'the kinetic or velocity energy of a fluid either in gaseous or liquid form is employed to remove fluid either in gaseous or liquid form, or in both of these forms combined, from a region at lower pressure and discharge it into a region at higher pressure.

An object of my invention is to provide a radial flow ejector which shall possess a high degree of uniformity and reliability in per formance under varying loads.

Another object of my invention. is to produce a radial flow ejector which shall maintain substantially uniform delivery pressures by causing the fluid to be entrained to flow in stream lines which meet tangentially moving streams of entraining fluid at an angle in a mannerto produce spiral'paths of the mixed fluids through the. diffuser of the ejector, the length of the spiral paths varying inversely with the load.

A still further object of my invention is to provide a radial flow ejector in which a greater economy of operation is obtained by velocity moving jet of motive fluid.

These and further objects, which will be made apparent throughout the description of my invention, are attained by means of the apparatus described herein and illustrated in the accompanying drawing, in which;

Fig. 1 is a diagrammatic sectional view of Fig. 2 is a similar view of a modification of the structure illustrated in Fig. 1;

Fig. 3 is a diagrammatic plan view of the device illustrated in Fig. 2;

Fig. 4 is a diagrammatic sectional view of another modification of the construction illustrated in Fig. 1;

Fig. 5 is a similar view of a further modiflcation of my invention;

Fig. 6 is a diagrammatic horizontal view of the apparatus illustrated in Fig. 5;

Figs. 7, 8 and 9 are diagrammatic sectional views of several modifications illustrating some of the ways in which the velocity of the fluid to be entrained may be increased prior to entrainment by the entraining fluid.

It is well known that with ejectors having diffusers of the usual radial type, satisfactory operation is usually only obtained when the ejectors are operating at or about full load, that is to say, when the quantities of fluids passing through them are approximately equal to those for which the ejector has been designed. At partial loads, either the efficiency of such an ejector falls very quickly or the operation of the device becomes unreliable. Owing to the fact that at partial loads the velocities in the diffuser of such an ejector are smaller in proportion to the decreased volume, the pressure to which the fluid can be compressed thereby is con siderably reduced.

I propose to employ,in a radial flow ejector, a nozzle construction which is arranged to discharge fluid tangentially into the throat of a radial diffuser, entraining the fluid to be evacuated, the latter fluid being delivered to the throat of the diffuser in such a manner that the stream lines of the entraining and entrained fluids meet at an angle. Since the force of the entraining jets is uniform, the union of the streams of the two fluids produces a component flow of mixed fluids in parallel spiral paths through the diffuser, the character of which are determined by the direction of flow and magnitude of the fluidsbeing entrained. Thus, the spiral paths are shorter at full loads than at light loads, the length of the paths varying inversely with the load. This construction and mode of operation insures a fair degree of uniformity in discharge pres sures of the fluids and consequently a high degree of efliciency and reliability in the operation of the ejector.

I further propose to give the fluid to be entrained an initial velocity before it mixes with the motive fluid, since the less the differences in the velocities of the entraining and entrained fluids, where they intermingle in an ejector, the better is the efliciency at which the ejector operates. The velocity of the fluid to be entrained is, therefore made as high as possible in that part of the ejector where it mixes with the entraining fluid. The increase oi velocity of the fluid to be entrained may be obtained by a corresponding loss in pressure and, in the case of gaseous fluids, with additional expansion and subsequent increase in the work of compression which has to be eiiected in the diffuser. To obviate such additional expansion in the throat of the diffuser, I provide means within the inlet passage for accelerating th velocity of the fluid to be entrained, the object of this accelerating means being not to compress the fluid but to prevent further expansion and at the same time cause it to have the highest possible velocity before the fluid meets the entraining fluid issuing from the main operating nozzle of the ejector. Where a fluid to be entrained is a liquid, the increasedvelocity may be obtained by increasing the height of the liquid column, or by producing an artificial vortex in the fluid entering the ejector. Obviously,

both of these means may be employed together.

These and other improvements in the operation of an ejector of the character designated I secure by the apparatus which will now be specifically described with reference to the several figures in the accompanying drawings which show diagrammatically various forms of ejectors constructed in accordance with my invention.

In Fig. 1 a simple form of the improved ejectoris shown comprising an inlet 1 for the entraining fluid leading to a ring of tangentially disposed nozzles 52 located at the apex of a conical diffuser 3 which terminates in a collecting chamber at having a discharge outlet 5. The fluid to be entrained is admitted through an inlet 6, also located at the apex oi the conical. difl'user 3 and surrounding the inlet 1 for the entrain ing fluid. In operation the entraining fluid admitted through the inlet 1 meets the fluid to be entrained entering through the inlet 6 at the exit of the ring of nozzles 2, the mixed. fluids then passing through the diffuser 3 in a substantially spiral path. At full load,

' the path of flow of the mixed fluids is much shorter than at light loads and in an extreme case the ejector may be so designed that at full load the path of flow of the mixed fluids is approximately a straight line from the apex to the base of the diffuser 3.

The conical form of diituser permits oi 1 of the ejector.

combined fluids are compressed in the diffuser 3 and discharged through the collecting chamber 4. The entraining fluid may be arranged to enter the ejector at a high tangential velocity which will be imparted to preferably shaped to hyperbolic curves.

The nozzles 2 for discharging the entraining fluid into the'difiuser 3 are arranged to discharge ets tangentially and in the direction of the diffuser 3. The hyperbolic curved portion of the fluid inlet is situated immediately above the throat of the diffuser so as to give the fluid to be entrained an increased Velocity before it is intermingled with the entraining fluid.

I indicate in Figs. 5 and 6 a construction in which the fluid to be entrained is given a spiral movement of increased velocity prior to entrainment in the jets from the main nozzles. As shown, the fluid to be entrained enters a vertically disposed inlet passage 6 which communicates with a central opening in a conical diffuser 8. A ring of nozzles 12 'enter the inlet 6 in a radial plane and give to the incoming fluid a rapid whirling motion. The main ejector nozzles 2 are lo cated so as to discharge jets of entraining fluid into the throat of the diffuser 3. The fluids pass in a spiral path through the diffuser 3 and are discharged into a collecting chamber 4 from whence theyare exhausted.

In the construction illustrated in Fig. 7 the inlet 6 for the .fluid to be entrained is arranged in an axial direction with respect to the difluser 3, the lower portion thereof being of decreased cross-sectional area to give the incoming fluid an increased velocity. In case the latter fluid is a liquid. a vortex is formed in its outlet from which the liquid is discharged at a considerable increased velocity. The motive fluid enters through the conduit 1 into an annular involute shaped passage 8, and is discharged with a whirling motion through the annular nozzle 7.

I show in Fig. 8 a means for increasing the velocity of the fluid to be entrained which consists in providing suitable helically disposed guides 14 in the inlet passage 6 for the fluid to be entrained and in contrac: ing said inlet passage 6 toward the throat The entraining fluid enters through an involu-te passage 8 and dis chargesjthrough an annular nozzle 7 into the throat of the diffuser 3. A collecting eham her 4: communicates with the diffuser 3 and is arranged to discharge the combined fluids in the usual manner. Theinixture of the two fluids should preferably take place in that part of the ejector in which the velocity ot the fluid to be entrained is the highest, that is, at the throat of the difluser, which is the point where the inlet passage should be the smallest. The smaller the size of the threat, the greater is the velocity of the fluid at that point and for this reason the throat should be as small as the maximum load for which the ejector is designed will warrant.

In Figure 9, I show a radial flow ejector in which the inlet passage 6 is annular in form. and decreases in cross-sectional flow area toward the throat of the diffuser 3. A ring of accelerating nozzles 15 extend into the annular portion of the inlet (i for the purpose of delivering jets of motive fluid to increase the rate of flow ot' the incoming fluid through the inlet 6. As shown, they are directed toward the throat of the ejector so as to give the incoming fluid a. spiral motion of considerable pitch. Entraining nozzles 2 discharge jets of entraining fluid tangentially into the throat of tl e difluser 3 which discharges the mixed fluids into a volute collecting chamber 4.

lVhile I have shown my invention in various forms, it will be obvious to those skilled in the art that it is not so'limited, but is susceptible of various other changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are lmposed by the prior art or as are specifically set forth in the appended claims.

I claim- 1. An ejector comprising an annular conical difluser having a fluid intake or throat at its apex and a tangentially disposed discharge at its base, a fluid nozzle disposed to discharge motive fluid through the throat into the difluser in a tangential direction, whereby conical-helical motion is imparted to the entrained fluid in passing through the diffuser, and means for imparting a rotary motion to the fluid to be entrained prior to its entrainment.

2. A11 ejector comprising an annular conical difluser having a fluid intake or throat at its apex, an intake passage communicating with said throat, means for discharging entraining fluid into the diffuser in a tangential direction, whereby conical-helical motion is imparted thereto, and means for imparting an accelerating movement to the fluid passing through said intake passage, whereby the difference in the velocities of the entrained and entraining fluids is diminished.

3. An ejector comprising an annular conical difluser having a throat at its apex and a fluid intake passage communicating with the throat, accelerating nozzles opening into the intake passage for discharging fluid to increase the velocity of the fluid to be entrained prior to entering the throat of the diffuser, and nozzles for entraining fluid arranged o discharge entraining fluid tangentially into the diffuser.

4. An ejector comprising an annular conical difluser having a throat portion at its apex, a nozzle arranged to discharge eu training fluid into the diffuser in a tangential direction, a substantially axial inlet passage for fluid to be entrained commumi-.

cating with said diffuser throat, said inlet passage having means for causing the fluid to be entrained to flow intosaid throat in tangential stream lines, which intersect at. an angle the tangential. stream lines of the motive fluid, whereby the length ct the spiral path of the mixed fluids varies inversely with the quantity o1" fluid entrained.

5. An ejector comprising an annular conical difluser having an intake or throat portion at its apex, an inlet passage communicating with said throat portion, means for discharging entraining fluid into the diffuser in a tangential direction, anti means in said inlet passage for increasing the velocity of the fluid to be entrained prior to its entrainment.

6. An ejector comprising an annular conical difluser having a throat portion at its apex, an inlet for fluid to be entrained communicating with said throat portion, means for discharging fluid into the diffuser for imparting a conical-helical motion thereto, and means for accelerating the velocity of the fluid to be entrained prior to entrainment, whereby-the velocity diflerences in the entrained and entraining fluids may be minimized.

7. An ejector comprising an annular conical diffuser having a throat portion at its apex, a nozzle arranged to discharge entraining fluid into the difluser in a tangential direction, an inlet passage for fluid to be entrained communicating with said throat portion, means for accelerating the velocity of said fluid within said inlet passage, said inlet passage having means for causing the fluid to be entrained to flow into said throat portion in stream lines which intersect at an angle the tangential stream lines of the motive fluid, whereby the length of the conical-helical path of the mixed fluids varies inversely with the quantity of the fluid entrained.

8. An ejector comprising an annular conical difluser having a throat portion at its apex, an inlet passage for fluid to be entrained communicating with said throat portion, a set of nozzles arranged in a radial plane to discharge jets of entraining fluid into said diffuser, and a second set of nozzles arranged in said inlet passage to increase the velocity of the fluid to be entrained prior to entrainment by said first set of nozzles.

&

9. An ejector comprising an annular conical diffuser having a throat portion at its apex, an axially disposed inlet passage for fluid to be entrained communicating With said throat portion, a set of nozzles ar ranged in a radial plane to discharge jets of entraining fluid tangentially into said diffuser, and a second set of nozzles discharging into said intake passage to increase the velocity of fluid to be entrained prior to entrainment by said first set of nozzles. 10. An ejector comprising an annular conical diffuser communicating at its apex with an inlet passage for fluid to be entrained, and a plurality of sets of nozzles'having their discharge openings arranged in separate planes traversing said inlet passage, at least one set of nozzles arranged to discharge motive fluid tangentially into said diffuser.

11. An ejector comprising an annular, diverging diffuser having a substantially central intake or throat, a substantially central inlet for fluid to be entrained communicating with said intake nozzle, means disposed in a radial plane for discharging entraining fluid into said diffuser, and a second nozzle means disposed in a radial plane separated from that of said first nozzle means for increasing the velocity of the fluid to be en: trained prior to entrainment by said first nozzle means.

12. An ejector comprising an annular divering diffuser having an intake or throat portion, an inlet passage communicating with said throat portion, means for discharging entraining fluid into the diffuser in a tangential direction, and means in said inlet passage for increasing the velocity of the fluid to be entrained prior to its entrainment.

13. An ejector comprising an annular diverging diffuser having a throat portion, an inlet for fluid to be entrained communicating with said throat portion, means for discharging fluid into the diffuser for imparting a conical-helical motion thereto, and means for accelerating the velocity of the fluid to be entrained prior to entrainment, whereby the velocity differences in the entrained and entraining fluids may be minie mized.

14., An ejector comprising an annular diverging diffuser having a throat portion, a nozzle arranged to discharge entraining fluid into the diffuser in a tangential direc-' tion, an inlet passage for fluid to be entrained communicating with said throat portion, means foraccelerating the velocity of said fluid Within said inlet passage, said inlet passage having means for causing the fluid to be entrained to flow into said throat portion in stream lines which intersect at an angle the tangential stream lines of the motive fluid, whereby the length of the conical-helical path of the mixed fluids varies inversely with the quantity of the fluid entrained.

In testimony whereof, I have hereunto subscribed my name this 20th day of Feb ruary, 1918. V

, KARL BAUMANN.

Witnesses:

JAMES HUT'roN, FREDERICK HIXON. 

